[Allen W. Wood] Kant's moral philosophy is grounded on the dignity of humanity as its sole fundamental value, and involves the claim that human beings are to be regarded as the ultimate end of nature. It might be thought that a theory of this kind would be incapable of grounding any conception of our relation to other living things or to the natural world which would value nonhuman creatures or respect humanity's natural environment. This paper criticizes Kant's argumentative strategy for dealing with our duties in regard to animals, but defends both his theory and most of his conclusions on these topics. /// [Onora O'Neill] Kant's ethics, like others, has unavoidable anthropocentric starting points: only humans, or other 'rational natures', can hold obligations. Seemingly this should not make speciesist conclusions unavoidable: might not rational natures have obligations to the non-rational? However, Kant's argument for the unconditional value of rational natures cannot readily be extended to show that all non-human animals have unconditional value, or rights. Nevertheless Kant's speciesism is not thoroughgoing. He does not view non-rational animals as mere items for use. He allows for indirect duties 'with regard to' them which afford welfare but not rights, and can allow for indirect duties 'with regard to' abstract and dispersed aspects of nature, such as biodiversity, species and habitats